textproduct: Rapid City

KEY MESSAGES

- Mild and dry today and Sunday. - Colder air mass arrives Tuesday with light rain/snow possible. - Cold persists through Thanksgiving into next weekend.

DISCUSSION

(Today Through Friday) Issued at 146 AM MST Sat Nov 22 2025

Water vapor imagery shows multiple shortwave troughs embedded within the northwest flow upstream of the forecast area. The first initial wave is quickly shifting east into the Upper Midwest with increased high level clouds across the forecast area. A second, stronger wave, is pushing into eastern MT and is forecast to push through ND later today. A surface trough will pivot through the region as this wave shifts through, bringing gusty (25-35 mph) northwest winds to the western SD plains this afternoon. Highs will be in the 50s with cooler temperatures in the higher elevations of the Black Hills and along the ND/SD border.

Warm air advection resumes overnight tonight into Sunday with dry west-southwest flow aloft resulting in a mild and sunny day to end the weekend; highs will be ~5-15F+ above normal Sunday afternoon.

Currently, a closed upper low is analyzed off the Baja Coast. This low will eject into the Central/Southern Plains overnight Sunday into Monday, clipping south-central SD. Light rain showers possible for south-central SD early Monday morning. Another shortwave is forecast to drop into the Northern Plains late Monday with a strong cold front to follow. This front will arrive late Monday night/early Tuesday with much colder air spilling into the Northern Plains. As this system pushes through, light rain/snow will transition to all snow through the day Tuesday, with accumulations limited to the higher terrain of the northern and Wyoming Black Hills (~35-40% probability of >1" snow per NBM probs). Advisory level winds are possible behind the front Tuesday across the western SD plains.

Ensembles and deterministic guidance both show decent agreement in a deeper trough to impact the central US by next weekend, although considerable track differences remain, limiting predictability in the precipitation forecast. Will continue to monitor the snow potential, although confidence is high that even colder air will filter into the region next weekend with ~30% chance of sub-zero temperatures Dec 1-2.

AVIATION

(For the 18Z TAFS Through 18Z Sunday) Issued At 1020 AM MST Sat Nov 22 2025

VFR conditions are expected through the TAF period.

UNR WATCHES/WARNINGS/ADVISORIES

SD...None. WY...None.